I. Field
The present disclosure relates generally to communication, and more specifically to techniques for deriving a channel estimate for a wireless channel.
II. Background
In a wireless communication system, a transmitter typically processes (e.g., encodes, interleaves, and symbol maps) traffic data to generate data symbols, which are modulation symbols for data. For a coherent system, the transmitter multiplexes pilot symbols with the data symbols, processes the multiplexed data and pilot symbols to generate a radio frequency (RF) signal, and transmits this RF signal via a wireless channel. The wireless channel distorts the transmitted RF signal with a channel response and further degrades the signal with noise and interference.
A receiver receives the transmitted RF signal and processes the received RF signal to obtain input samples. For coherent data detection, the receiver estimates the response of the wireless channel based on the received pilot and derives a channel estimate. The receiver then performs data detection (e.g., equalization) on the input samples with the channel estimate to obtain symbol estimates, which are estimates of the data symbols transmitted by the transmitter. The receiver then processes (e.g., demodulates, deinterleaves, and decodes) the symbol estimates to obtain decoded data.
The quality of the channel estimate may have a large impact on data detection performance and may affect the quality of the symbol estimates as well as the reliability of the decoded data. There is therefore a need in the art for techniques to derive a high quality channel estimate in a wireless communication system.